Edge‐Fluorinated Flower‐Like Porous Graphene Microspheres With Enlarged Interlayer Spacing for High‐Performance Potassium‐Ion Batteries

ABSTRACT The utilization of carbonaceous anodes in electrochemical systems, particularly potassium‐ion batteries (PIBs), remains hindered by sluggish kinetics and modest capacities, which are caused by the intrinsic ion storage mechanisms and constrained interlayer spacings. Herein, a novel flower‐like porous graphene microsphere, composed of edge‐fluorinated nitrogen‐doped graphene nanosheets (FNGS), has been developed through the synergistic engineering of morphology and interlayer spacing. This innovative design endows FNGS with three‐dimensional conductive networks, abundant ion transport channels, and enlarged interlayer spacings for efficient K storage. Leveraging these advantages, the FNGS anode achieves a high specific capacity of 439.0 mAh g −1 at 100 mA g −1 and exhibits excellent long‐term cycling stability over 400 cycles at 500 mA g −1 . Moreover, K‐ion full cells assembled with FNGS demonstrate a remarkable practical energy density of 321.7 Wh kg −1 at 100 mA g −1 and a power density of 8344.0 W kg −1 at 5000 mA g −1 , outperforming many previously reported results. Extensive experimental studies and theoretical calculations have systematically elucidated that the superior performance of FNGS is attributed to their surface‐dominated K storage mechanism, fast K + transport kinetics, and high structural reversibility. This work presents a compelling synergistic strategy for developing cost‐effective and robust carbonaceous anodes suitable for next‐generation battery technologies.